New guy here from mass bought my first dsm, few problems

[davetheman81]

hows it going, im Dave from Randolph, ma i just bought my first dsm yesterday its a 90 talon tsi front wheel, with 2g pistons and 1 g rods and 16g turbo built 15k ago and thats about it, it runs well when driving but idles bad, feels like a vacuum leek but someone told me probably iac it idles at 1300 and goes up and down from 1300-700 and back and the boost guage follows the tach, also after driving the car for about 5 minutes, all you can smell is exuast in the car, there has got to be a leak, does anyone have a good way of pin pointing the leaks in between the motor and exhaust, thanks - dave

also
the car does boost excellent im running it at 12 pounds, do you think after i fix the current issues i can raise it slightly towards 14-15 pounds thanks

 

[Lofty]

There's a good possibility after fixing these issues your boost WILL rise to 14 psi. Exhaust leaks hmm.

Check if the manifold is all tight and check, no leaking!
Start the car, let it run, place hand over all exhaust piping areas, if you feel hot puffs on your hand, that's where the leak is. That's the only way I've ever checked for leaks and it's been working fine for me.
Step one. Are you venting your blow off valve?
Step too. You have a 90. If it's a stock 90 intake manifold and throttle body, you're in for a treat. It's a little more difficult to replace your ISC or IAC motor with the 90's D:
What you have is Idle surge. If you follow the following link properly, you will have your issues solved. I guarantee it sir.
Terry's Talon Troubleshooting Tips #3 - Fast Idle (aka. Idle Surge)

This is a "hack" way to solve some problems.
You can try unplugging your isc. See what happens.
With a bad ISC there is a SLIGHT possibility you can fry your ecu. So get it fixed soon regardless.
My suggestion. Make sure you have ALL the maintenance done on this car before you touch mods.
Timing belts. Do it anyways unless you have receipts of when it was done last from the previous owner. It gives you piece of mind, and is a relatively cheap investment to avoid having your valves smack your pistons.

Any other problems/questions/concerns, feel free to pm me. Take care, good luck!

 

[davetheman81]

wow that was quick, thank you very much for the response, i only registered 10 mins ago , its a 90 with factory throttle body and manifold, blow off valve is routed into the intake pipe i will check that link out and get back to you with my results again thanks!

 

[Lofty]

Not a problem, I'm one of the few late night/early morning lurkers.

Good luck!

 

[davetheman81]

update! ok so i went under the hood and unplugged (i know this sounds bad) "something from the throttle body which i believe was the isc, started the car, and the idle is steady now, a little high but steady no surge, also i noticed the exhaust does smell better. I found the exhuast leak at the down pipe , and i will get a new gasket to take care of that, here are the pictures of what i unplugged from the t body, the plug was actually against the fire wall but i traced it to what i think is an isc, so does this mena i should replace the isc, i did get a check engine light after i unplugged it - thanks dave, also i dont no how to upload pictures yet so i had to photo bucket them

http://i13.photobucket.com/albums/a262/staticxtant81/2010-06-16144355.jpg
http://i13.photobucket.com/albums/a262/staticxtant81/2010-06-16144402.jpg

 

[Lofty]

That looks to be the ISC. And yeah, it idles higher, but won't stall. So it's a win/lose situation.

 

[davetheman81]

ok but is it same to run my car with the isc unplugged ### i now have a cel

 

[supravw]

It's perfectly safe to unplug it and leave it that way. It's been awhile sense I had a 90 but I have never had a CEL come on from unplugging any of the sensors on the throttle body. I normally get a block of plate and eliminate all the sensors except the TPS on the front. The result is a steady idle and you just adjust it up or down with the BISS screw. But be careful with the BISS screw as they LOVE to strip. I would suggest replacing it and the oring as that's a common boost leak source.